Various configurations of burner arrangements are known from the prior art. During operation of a burner arrangement, such as for example the burner arrangement of a gas turbine, thermoacoustically induced combustion oscillations arise in the combustion chamber. These may excite components of the burner arrangement to oscillate. If an exciting oscillation coincides with a resonant frequency of the burner arrangement or the components thereof, this may result in the destruction of components. Excitation of the burner arrangement and the components thereof in the range of such resonant frequencies must accordingly be avoided.
It is already known to modify the acoustic characteristics of burner arrangements and the components thereof by installing resonators which operate according to the Helmholtz principle. Thus, for example, document EP 2 559 942 A1 discloses a resonator which is arranged in the combustion chamber hood or in the region of the cooling air feed line. A disadvantage of such an arrangement lies, however, in the fact that damping does not take place directly at the point of origin of the oscillation in the region of the combustion chamber and is thus of low efficiency.
It is also known to place resonators directly on the circumference of the combustion chamber wall. This allows effective damping in the region of heat release. However, such resonators must be cooled with a large volumetric flow rate of cooling air. This air is no longer directly available for the combustion process, which leads to higher NOx emissions.
To reduce this problem, EP 1 792 123 B1 proposes guiding compressed air into the combustion chamber through resonator devices incorporated into the combustion chamber wall. The advantage of this design lies in the coupling of wall cooling and resonator purging and in incorporating medium and high frequency resonators in the combustion chamber wall. A disadvantage, however, is the double-walled embodiment of the combustion chamber wall, which entails significant constructional effort and high costs.
Document EP 1 481 195 B1 proposes arranging resonators between a fuel introduction point and the combustion chamber. However, this represents direct influencing of the fuel mass flow rate, which is considered disadvantageous. Furthermore, resonators configured in this way are not suitable for covering a broad frequency range.
EP 0 597 138 A1 describes a gas turbine combustion chamber which comprises air-purged resonators distributed in the circumferential direction in the region of the combustion chamber inlet. Here too, however, the problem arises that the cooling air is not directly available for combustion and NOx emissions therefore rise.